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From:   Alexander Egorenkov <egorenar-dev@posteo.net>
To:     linux-kernel@vger.kernel.org
Cc:     Alexander Egorenkov <egorenar-dev@posteo.net>
Subject: [PATCH 1/2] lib: scatterlist: Fix loop termination condition in sg_calculate_split()
Date:   Sun, 18 Apr 2021 14:34:24 +0000
Message-Id: <20210418143425.22944-1-egorenar-dev@posteo.net>
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nb_splits was decremented one time too much becoming negative. This
leads to the failure of the loop termination conditions which checks
only for nb_splits being zero. Move the loop termination condition
a couple of lines up before nb_splits is decremented again and potentially
becomes negative.

Signed-off-by: Alexander Egorenkov <egorenar-dev@posteo.net>
---
 lib/sg_split.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/lib/sg_split.c b/lib/sg_split.c
index 3d9b32084d78..0920affd12ee 100644
--- a/lib/sg_split.c
+++ b/lib/sg_split.c
@@ -60,15 +60,16 @@ static int sg_calculate_split(struct scatterlist *in, int nents, int nb_splits,
 			curr->length_last_sg = len;
 			size -= len;
 		}
-		skip = 0;
-
-		if (!size && --nb_splits > 0) {
-			curr++;
-			size = *(++sizes);
-		}
 
 		if (!nb_splits)
 			break;
+
+		skip = 0;
+
+		if (!size && --nb_splits > 0) {
+			curr++;
+			size = *(++sizes);
+		}
 	}
 
 	return (size || !splitters[0].in_sg0) ? -EINVAL : 0;
-- 
2.31.1